The aim of this study was to investigate the role of nephrocalcin in childhood urolithiasis. Forty-one patients with urinary stones and 25 age- and sex-matched healthy controls were admitted to the study. Blood and timed urine samples were taken from both patient and control groups for biochemical analysis. Serum and urine creatinine (Cr) and urinary nephrocalcin (NC) were measured. NC excretion was expressed as a NC/Cr (mg/g) ratio. NC-PreA/Cr and NC-D/Cr ratios were found to be significantly higher in patients than in the control group. No statistically significant differences were found in NC-A/Cr, NC-B/Cr, NC-C/Cr ratios between the patient and control groups. The high NC-PreA/Cr ratio (p = 0.012) observed in stone-forming patients indicates that this ratio may also be an important stimulatory factor for urinary stone disease.